Computer Simulation of an Engine Environmental Control System

2013 ◽  
Vol 850-851 ◽  
pp. 355-358
Author(s):  
Dong Du

This paper describes the use of Fluid Flow Simulation Software to model a passenger aircraft engine environmental control system. The analysis simulates the cooling pack and the engine distribution system in a single model.The engine environmental system is very important for engine working efficiently. Using AMEsim software to simulate the cooling system can make it easily and clearly. The influence of the heat component and the fan operating is studied also. Through the analysis of the cooling system, we know that with the help of fan, the system can get additional air in the radiator and make the temperature decrease consequently.

Author(s):  
Michel Engelhardt

An Environmental Control System (ECS) concept is developed to control the temperature of an Electronic System (ES) and to cool the airborne system Electronic Units (EUs). These units are integrated into a Pod that is attached to the centerline station of a fighter aircraft. The objective of this paper is to describe the thermal control system concept used to control the ES bay air temperature, humidity, and pressure; and the cooling system used to cool the EUs. Another objective of this paper is to provide a summary of the thermal-fluid analytical models and the ECS performance predictions. The main components of the ECS are based on vapor cycle cooling. The EUs that support system management and recording are air-cooled. Ground operations are accomplished through the autonomous ECS thermal control of the ES and fan cooling of the EUs. Thermal analyses at aircraft operational altitudes and speeds predict that the ES temperature is controlled within ±5°C of its temperature at take-off by the ECS. ES bay temperatures are held between preset lower and upper bound ES temperatures during the required MIL-STD-210A tropical day without condensation of moisture in the ES bay. In addition, thermal analyses indicate that the EUs are cooled throughout ground and airborne operation to ensure that electronic components are below their manufacturers’ rated temperature requirements.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.


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